FQE Chemicals Blog

Scaling is a common problem frequently encountered in oil and gas production, petroleum refining and other industrial operations where water is encountered or used. Some of the most common scales encountered in the production or refining of oil are calcium carbonate, calcium sulfate and barium sulfate. Other less common scales are strontium sulfate, iron (II) carbonate, iron (II) sulfide, Iron (II) hydroxide, iron (III) hydroxide and iron (III) oxide.

Catalysis plays a key role in petroleum refining as most of the processes beyond the crude unit are catalytic. Since most straight-run fuels produced through fractional distillation do not meet the quality requirements for low-sulfur and higher-octane fuels, most of the crude unit fractions are further processed. Gasoline with anti-knocking characteristics is made with catalytic cracking of heavy hydrocarbons of selective catalysts and zeolites. Gasoline with low aromatic content (benzene/naphthalenes) comes from alkylation of light olefins with isobutane in the presence of hydrogen and metallic catalysts. The catalytic addition of hydrogen to atmospheric tower fractions results in the removal of Sulfur and Nitrogen and unsaturated compounds (olefins) via the Hydrotreating process. Increases in fuel octane numbers come from catalytic reforming and isomerization processes both of which are also catalytic in nature. Upgrading of heavy hydrocarbon streams through hydrocracking into lighter hydrocarbon molecules is catalytic.

Hydrogen Sulfide is a toxic, colorless gas that is invisible, explosive, flammable, heavier than air and a leading cause of fatalities in the oil and gas and petrochemical industries. It is formed when organic material decomposes. At low concentrations, it has an offensive odor of rotten eggs. At high concentrations, it deadens your sense of smell. It is corrosive to metals having two active protons making it acidic in nature. It combines with iron to form iron sulfides which are often pyrophoric and can be the cause of fires in processing and storage equipment.

In the previous article we discussed the concept and use of foams as an effective cleaning methodology. Part two is about chemical solvents, inhibitors, foaming agents and other aspects of the foam cleaning methodology.

Foam cleaning represents a unique application of a technological extension of conventional chemical cleaning methodology. It is extremely well suited to the cleaning of large volume equipment and structures which are unable to support the weight of conventional liquid solvents. The same solvents used in common liquid-fill cleaning operations are again employed. The major difference is the addition to the liquid solvent of a suitable foaming agent. The surfactant convers stability to the foam which is generated by mixing air with the common solvent.

As the popularity of the automobile increased during the early 1900’s, the demand for the gasoline portion of a barrel of oil proportionally increased. It quickly became apparent that meeting the market demands for straight-run gasoline would result in a glut in the marketplace of the heavier fuel oil crude fractions. In response to how to make use of the heavier hydrocarbon streams to increase the amount of gasoline range product available, several “cracking” techniques were developed. The most popular of the cracking techniques is catalytic (“cat”) cracking.

Petroleum refining and oil and gas production operations generate both oil-in-water (O/W) and water-in-oil (W/O) emulsions. These emulsions are present in produced hydrocarbon fluids, drainage water, separator equipment, tank bottoms, and various oil recovery devises. In the petrochemical industry quench waters generated in ethylene and other olefin manufacturing operations may contain various hydrocarbons from heavy to light.

In a previous discussion about Hydrotreating, we talked about the types of fouling present in various parts of the hydrotreater. We did not address the catalytic reactor and cleaning of reactor internals of hydrocarbon liquids and heavier hydrocarbon deposits.

As we have been discussing petroleum refining processes and the various problems that are encountered during decontamination and shut-down preparations, we have taken side trips to talk of related subjects such as pyrophoric iron, degassing and other matters. One of these side discussions was about asphaltenes. Two other constituents of crude oil that have impact on petroleum refining operations are resins and polymers.

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This blog serves as a way to share insights into the world of chemistry, and talk about the latest industry news. Our posts are written by our own industry renowned chemist, Doug Mason, M.Sc., Organic Chemistry.

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